The 100 Most Mentioned Glaucoma Articles Online With Highest Altmetric Attention Scores.

PRCIS: Characteristics of the most mentioned glaucoma articles on the internet were analyzed, allowing a better understanding of the dissemination of glaucoma research to the general public. PURPOSE: The aim was to determine the 100 most mentioned articles on the internet in the field of glaucoma and analyze their characteristics. MATERIALS AND METHODS: We identified the top 100 glaucoma articles with the highest Altmetric Attention Score (AAS), an automatically calculated metric for monitoring social media. Each article was evaluated for several characteristics including year of publication, title, journal name, journal impact factor (IF), article topic, article type, affiliation, and online mentions (news, blog, policy, Twitter, Facebook, etc.). Correlation analysis was conducted for AAS with these characteristics. RESULTS: The selected 100 articles came from 44 journals with more than half (56%) published in ophthalmology-specific journals. There was no significant correlation between IF and number of articles in a specific journal or AAS (P>0.1), but the number of articles in the top 100 was higher for ophthalmology journals with a higher IF (P<0.05). Original study was the most common study type (87%), of which clinical observation study was the most common subgroup (40%). Epidemiology/risk factor and basic science were the most common article topics (each 24%), followed by medical treatment (13%). Article topics regarding medical treatment had a significantly greater AAS than other topics (P<0.05). Of the top 5 articles, more than half (60%) were related to "Lifestyle choice" topics. CONCLUSIONS: There was no association between journal IF and AAS, consistent with previous studies. 90% of journals that had articles in the top 100 had a Twitter page. "Lifestyle choice" activities and other modifiable risk factors attracted significant online attention regarding glaucoma studies, with two of the top three most mentioned articles related to dietary intake. The present study thus provides a better understanding of online engagement with glaucoma research and the dissemination of this research to the general public.

A comprehensive analysis of authorship trends in Skeletal Radiology since inception from 1976 to 2020.

OBJECTIVE: The purpose of this study is to explore authorship trends within the musculoskeletal radiology subspecialty-focused journal, Skeletal Radiology, from inception to 2020. MATERIALS AND METHODS: Skeletal Radiology articles published in 1976, 1986, 1996, 2006, 2016, and 2020 were reviewed. For each article, the number of authors, the number of distinct institutions, the names of first and last authors, the country of the first author, the article length, and the number of article references were recorded. RESULTS: A total of 885 articles passed the exclusion criteria to be included in the study. Since inception, there has been a significant increase in the number of SR articles published (P = 0.02), the mean number of authors per article (P < 0.01), the mean number of references per article (P < 0.01), the mean number of distinct institutions per article (P = 0.02), and the mean number of pages per article (P < 0.01). The proportion of female first and last authors significantly increased (P = 0.02, P = 0.02). There was a significant increase in the proportion of articles published from Asia (P = 0.04). However, no significant changes in the proportion of articles published from other regions were observed. CONCLUSION: Similar to authorship trends in other medical journals, Skeletal Radiology demonstrated upward trends in authorship count, distinct institutional count, and article length. A rise in first and last female authorship was observed. Finally, an increase in the proportion of authors from Asia was observed while no significant changes in the proportion of authors from other regions were demonstrated.

Evaluating Neuroradiology Fellowship Program Websites: A Critical Analysis of all 84 Programs in the United States.

PURPOSE: To investigate the accessibility and content of neuroradiology fellowship program websites (NRFW). METHODS: A list of neuroradiology fellowship programs were obtained from the official Accreditation Council for Graduate Medical Education (ACGME) website. A google search was used to identify each NRFW of individual programs. Each NRFW was evaluated for the availability of content under recruitment and education domains. RESULTS: At the time of the study, there were 84 ACGME accredited neuroradiology fellowship websites available for analysis. In the recruitment domain, evaluators found program description (98.8%), contact address (94.1%), and searchable on google (97.7%) most readily available while, interview day itinerary (3.5%), meal allowance (16.5%), and parking (21.2%) were least readily available. In the education domain, research (91.8%), facility description (89.4%), and faculty listing (82.4%) were most readily available, while postfellowship placement (10.6%), alumni education history (17.7%), and responsibility progression (25.9%) were least readily available. CONCLUSIONS: NRFW vary greatly in the amount of information they display. Programs display their descriptions and contact information most frequently while interview day itinerary was the least likely to be found. There were no statistically significant differences between the amount of recruitment and educational content listed when programs were stratified by rank (top ten vs below top ten), region (west, midwest, northeast, and south), and program size (>3 fellows vs 1-3 fellows). Website content development is relatively low cost and our findings suggest that there is room for improvement in website comprehensiveness.

Trends in Authorship of Original Scientific Articles in Journal of Glaucoma: An Analysis of 25 Years Since the Initiation of the Journal.

PRéCIS:: Publications in glaucoma have seen an increase in the number of authors and disclosures per article, authors with dual degrees, and international authors, but contributions of women to articles published remains low. PURPOSE: Authorship trends have been studied across many medical specialties and in ophthalmology as a whole, but not specifically in glaucoma. The authors explored the authorship trends of original scientific articles in the Journal of Glaucoma. MATERIALS AND METHODS: The authors recorded the number of authors and disclosures per article, degree type of first and last authors, geographical origin of the corresponding author, and sex of first and last authors of original content from the Journal of Glaucoma published in 1992, 1997, 2002, 2007, 2012, and 2017. RESULTS: A total of 642 articles were analyzed. From 1992 to 2017, annual published articles increased from 38 to 242 (P=0.02), the mean number of authors per article increased from 3.2 to 5.2 (P<0.01), the mean number of disclosures per article increased from 0.3 to 1.0 (P=0.04), the proportion of first and last authors with dual degrees (medical plus advanced degrees) also increased (both P<0.03), whereas the proportion with a sole medical degree decreased (both P<0.05). There was a proportional decrease in articles from North America (P=0.03), and proportional increase from the "Far East" (P=0.04) and "Other" regions (P=0.04). No significant changes in proportions of female first and last authors were found (both P>0.28). CONCLUSIONS: Consistent with authorship trends across various other medical specialties, glaucoma has seen an increase in the number of authors and disclosures per article, authors with dual degrees, and authors from the "Far East" and "Other" regions. However, contributions of women to articles published in Journal of Glaucoma remain low.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY DETECTS SUBCLINICAL RADIAL PERIPAPILLARY CAPILLARY DENSITY REDUCTION AFTER PLAQUE RADIOTHERAPY FOR CHOROIDAL MELANOMA.

PURPOSE: To evaluate radial peripapillary capillary density (RPCD) in irradiated eyes without radiation papillopathy clinically. METHODS: Patients treated with plaque radiotherapy for unilateral choroidal melanoma without radiation papillopathy clinically received optical coherence tomography and optical coherence tomography angiography imaging at ∼12- to 24-month follow-up. Comparison of RPCD globally and meridian closest to plaque and meridian farthest to plaque of irradiated versus nonirradiated eyes was performed. RESULTS: Mean age was 55 years (n = 10). Mean largest basal diameter and thickness were 10.1 and 4.4 mm, respectively. Mean radiation dose to the optic nerve head and foveola was 41.7 and 66.2 Gy, respectively. No radiation papillopathy was detected by ophthalmoscopy throughout follow-up (mean:14 months). Radial peripapillary capillary density was significantly reduced globally (all P < 0.02). Meridian closest to plaque RPCD was significantly reduced (P < 0.01), but not meridian farthest to plaque RPCD (P = 0.07). Circumpapillary retinal nerve fiber layer thickness was not significantly reduced (P > 0.26). Radiation dose to the optic nerve head was correlated with meridian closest to plaque RPCD reduction (r = 0.76; P < 0.01). Mean radiation dose to the optic nerve head for <5% and ≥5% RPCD reductions was 35.9 ± 12.2 and 55.2 ± 6.4 Gy, respectively. CONCLUSION: Radial peripapillary capillary density reduction was found in irradiated eyes before clinical evidence of radiation papillopathy and circumpapillary retinal nerve fiber layer thickness reduction. Radial peripapillary capillary density reduction is correlated to plaque location and radiation dose to the optic nerve head.

Uncontrolled recurrent myasthenia gravis exacerbations secondary to chronic gabapentin use.

Gabapentin is an anticonvulsant medication that reduces synaptic transmission by decreasing presynaptic voltage-gated Ca2+ and Na+ channels. It is approved to treat focal seizures but also used to treat post-herpetic and neuropathic pain. Although uncommon, there have been three reported cases of myasthenia gravis exacerbation associated with gabapentin in the literature. We present a patient with uncontrolled recurrent myasthenia gravis exacerbations secondary to chronic gabapentin use and provide a review for the three published cases.

Changes in Iridocorneal Angle and Anterior Chamber Structure in Eyes With Anatomically Narrow Angles: Laser Iridotomy Versus Pilocarpine.

PURPOSE: To compare the effects of laser iridotomy (LI) and pilocarpine on iridocorneal angle and anterior chamber structure in anatomically narrow angles (ANAs). MATERIALS AND METHODS: Temporal LI was performed 90 minutes after 2% pilocarpine administration in patients with occludable ANA. Swept-source optical coherence tomography B-scans of the anterior segment were obtained at baseline, 60 minutes after 2% pilocarpine administration, and 1 week after LI. Angle-opening distance (AOD), trabecular-iris surface area (TISA), and angle recess area (ARA) were measured at the temporal, superior, nasal, and inferior quadrants. Anterior chamber depth (ACD) and lens vault (LV) were also measured. AOD, TISA, ARA, ACD, and LV were compared among 3 time points: at baseline, 60 minutes after 2% pilocarpine administration, and 1 week after LI. RESULTS: Twenty-four eyes (24 patients; mean age, 55 y) were included. In all 4 quadrants and globally, AOD, TISA, and ARA increased from baseline after pilocarpine and after LI (all P<0.010). The increase in AOD, TISA, and ARA was greater after LI than after pilocarpine globally and in the temporal and superior quadrants (all P<0.040). ACD decreased and LV increased from baseline after pilocarpine (both P<0.001). Postpilocarpine anterior chambers were shallower with higher LV than post-LI (both P<0.016). CONCLUSION: LI is more effective than pilocarpine in widening the iridocorneal angle without significant shallowing the anterior chamber in eyes with ANA.

Optical Coherence Tomography Angiography Features of Iris Racemose Hemangioma in 4 Cases.

Importance: Optical coherence tomography angiography (OCTA) allows visualization of iris racemose hemangioma course and its relation to the normal iris microvasculature. Objective: To describe OCTA features of iris racemose hemangioma. Design, Setting, and Participants: Descriptive, noncomparative case series at a tertiary referral center (Ocular Oncology Service of Wills Eye Hospital). Patients diagnosed with unilateral iris racemose hemangioma were included in the study. Main Outcomes and Measures: Features of iris racemose hemangioma on OCTA. Results: Four eyes of 4 patients with unilateral iris racemose hemangioma were included in the study. Mean patient age was 50 years, all patients were white, and Snellen visual acuity was 20/20 in each case. All eyes had sectoral iris racemose hemangioma without associated iris or ciliary body solid tumor on clinical examination and ultrasound biomicroscopy. By anterior segment OCT, the racemose hemangioma was partially visualized in all cases. By OCTA, the hemangioma was clearly visualized as a uniform large-caliber vascular tortuous loop with intense flow characteristics superimposed over small-caliber radial iris vessels against a background of low-signal iris stroma. The vascular course on OCTA resembled a light bulb filament (filament sign), arising from the peripheral iris (base of light bulb) and forming a tortuous loop on reaching its peak (midfilament) near the pupil (n = 3) or midzonal iris (n = 1), before returning to the peripheral iris (base of light bulb). Intravenous fluorescein angiography performed in 1 eye depicted the iris hemangioma; however, small-caliber radial iris vessels were more distinct on OCTA than intravenous fluorescein angiography. Conclusions and Relevance: Optical coherence tomography angiography is a noninvasive vascular imaging modality that clearly depicts the looping course of iris racemose hemangioma. Optical coherence tomography angiography depicted fine details of radial iris vessels, not distinct on intravenous fluorescein angiography.

A Novel Method for Assessing Lamina Cribrosa Structure Ex Vivo Using Anterior Segment Enhanced Depth Imaging Optical Coherence Tomography.

PURPOSE: The purpose of this study is to investigate the use of anterior segment enhanced depth imaging (EDI) optical coherence tomography (OCT) for ex vivo lamina cribrosa (LC) imaging. MATERIALS AND METHODS: After removing anterior segment and vitreous, the optic nerve head (ONH) tissue of porcine eyes was placed on a customized eye holder for imaging. Serial EDI OCT B-scans (interval, ∼35 µm) of the ONH were obtained using anterior segment module of spectral-domain OCT. Various conditions were tested for better quality LC images. After EDI OCT, serial histologic sections were obtained (distance between sections, ∼5 µm). LC structures in OCT scans were compared with those in histologic sections. Three-dimensional LC reconstructions created using serial OCT scans were compared with LC structures in disc photographs. RESULTS: ONHs of 3 enucleated eyes were examined. The LC was more clearly imaged when the retina and part of the prelaminar tissue were removed (quality score, 39.01±3.30 vs. 26.40±5.85; P<0.001) and when the tissue was kept moist during imaging (quality score, 38.70±2.11 vs. 36.18±5.98; P<0.001). LC image quality was similar before and after fixation (quality score, 38.84±6.57 vs. 39.21±9.69; P=0.79). LC beams and part of retrolaminar glial columns identified in OCT scans matched those in histologic sections. LC beams and pores in 3-dimensional reconstructions matched those in disc photographs. CONCLUSIONS: High-resolution cross-sectional images of the LC, comparable to histologic sections, can be obtained using anterior segment EDI OCT in ex vivo eyes with proper tissue preparation.

Conjunctival Tumors: Review of Clinical Features, Risks, Biomarkers, and Outcomes--The 2017 J. Donald M. Gass Lecture.

Conjunctival tumors encompass a broad range of diagnoses. The 3 most important malignant tumors include ocular surface squamous neoplasia (OSSN) (14%), melanoma (12%), and lymphoma (7%). Conjunctival malignancies are rarely found in children. Regarding OSSN, pre-disposing conditions include chronic solar radiation, immune deficiency (HIV), organ transplant, autoimmune conditions, xeroderma pigmentosum, and chronic exposure to cigarette smoke. OSSN is managed surgically or with topical/injection immunotherapy or chemotherapy. Metastasis occurs in <1%. Regarding melanoma, predisposing conditions include primary acquired melanosis (PAM), chronic nevus, and chronic solar radiation. Treatment of PAM or nevus can prevent melanoma. Melanoma management involves surgical resection with clean margins and avoidance of direct tumor manipulation ("no touch" technique). The first surgery is most important, to minimize tumor seeding. Biomarkers including BRAF, TERT, and PTEN provide information regarding risk for metastasis and allow for targeted antibiomarker therapies. Ten-year risk for melanoma metastasis is 25%. Tumors >2 mm thickness or those located in fornix, caruncle, or orbit are at highest risk for metastasis. Regarding lymphoma, predisposing conditions include benign reactive lymphoid hyperplasia, immune deficiency (HIV), immune dysfunction, and chronic inflammation/infection (Helicobacter pylori, Chlamydia psittaci). The 4 most important subtypes include extranodal marginal zone lymphoma (ENMZL), follicular lymphoma, mantle cell lymphoma (MCL), and diffuse large B-cell lymphoma. Treatment includes surgical resection, cryotherapy, radiotherapy, systemic chemotherapy, or targeted anti-B-cell therapy (rituximab). Lymphoma-related survival (5-year) depends on subtype and ranges from 97% (ENMZL) to 9% (MCL). Recognizing conjunctival tumors and understanding predisposing factors, biomarkers, and treatment strategies are vital to patient outcomes.

Glaucoma Diagnostic Capability of Circumpapillary Retinal Nerve Fiber Layer Thickness in Circle Scans With Different Diameters.

PURPOSE: To compare varying circumpapillary optical coherence tomographic (OCT) scan diameters for glaucoma diagnosis. MATERIALS AND METHODS: Prospective, cross-sectional, observational study. Circumpapillary retinal nerve fiber layer thickness (RNFLT) was measured using spectral-domain OCT in 1 randomly selected eye. Scans with diameters of 3.5, 4.1, and 4.7 mm were obtained, each with 7 parameters: mean global (G) RNFLT and mean RNFLT for the temporal-inferior (TI), nasal-inferior (NI), temporal-superior (TS), nasal-superior (NS), nasal (N), and temporal (T) sectors. Areas under the receiver operating characteristic curve (AUCs) were calculated. RESULTS: Mean age was 55±18 years in 68 healthy eyes and 59±15 years in 95 glaucomatous eyes (P=0.12). Visual field mean deviation was -7.55±6.61 dB in glaucomatous eyes. In all 3 circle scans, mean TI RNFLT had the greatest AUC (0.974 to 0.983), followed by mean G RNFLT (0.949 to 0.956). The AUC of mean TI RNFLT in the 4.1-mm scan (0.983) was greater than the AUCs of mean TI RNFLTs in the 4.7- (0.978; P=0.128) and 3.5-mm (0.974; P=0.049) scans. The AUC of mean TI RNFLT in the 4.1-mm scan (0.983) was greater than the AUCs of mean G RNFLTs in the 3.5- (0.954; P=0.011), 4.1- (0.956; P=0.016), and 4.7-mm (0.949; P=0.011) scans. In 2 eyes with large parapapillary atrophy, RNFL segmentation error was noted only in the 3.5-mm scan in the area of parapapillary atrophy. CONCLUSIONS: Further investigations to find the spectral-domain OCT circle scan diameter with the best diagnostic capability and the least artifacts are warranted, especially focusing on larger-than-conventional circle scans.

Choroidal nevus: a review of prevalence, features, genetics, risks, and outcomes.

PURPOSE OF REVIEW: To review the prevalence, clinical features, imaging findings, cytogenetics, and risks and outcomes of choroidal nevus. RECENT FINDINGS: Choroidal nevus is a benign melanocytic tumor, often discovered incidentally on ophthalmic examination. This lesion is generally well circumscribed and pigmented. The prevalence of choroidal nevus in postequatorial region in United States adults (≥40 years old) is approximately 5%. Choroidal nevus is associated with higher lifetime unopposed estrogen and greater BMI. In population-based evaluation, the mean nevus basal dimension is approximately 1.25 mm. Giant nevus (basal dimension ≥10 mm) carries greater risk for malignant transformation. Imaging modalities for evaluation of choroidal nevus include ultrasonography, fundus autofluorescence, and optical coherence tomography (OCT). Fluorescein angiography is occasionally employed to detect multifocal pinpoint leaks or choroidal neovascular membrane. Recently, OCT angiography demonstrated nevus with minimal overlying macular microvascular changes compared with melanoma. Cytogenetically, GNA11 or GNAQ mutations have been documented in uveal melanoma in 83% and in some cutaneous nevus subtypes. Further mutations lead to the development of melanoma at a rate of one of 8845 cases. Risk factors for transformation of nevus into melanoma are recalled by the mnemonic 'To find small ocular melanoma using helpful hints daily' representing thickness (T) more than 2 mm, subretinal fluid (F), symptoms (S) of flashes/floaters/blurred vision, orange (O) lipofuscin pigment, margin (M) less than 3 mm from optic disk, ultrasonographic hollowness (UH), halo (H) absence, and drusen (D) absence. The presence of three or more risk factors implies more than 50% chance for transformation to melanoma within 5 years. A new, online ocular oncology reading center can help judge nevus risk. SUMMARY: Choroidal nevus is a common intraocular lesion, found predominantly in Whites. This mass carries a small risk (<1%) for malignant transformation. Patients with at least three risk factors should be evaluated for possible melanoma at an experienced ocular oncology center.

Microarchitecture of Schlemm Canal Before and After Selective Laser Trabeculoplasty in Enhanced Depth Imaging Optical Coherence Tomography.

PURPOSE: To characterize the in vivo effect of selective laser trabeculoplasty (SLT) on the Schlemm canal (SC) in eyes with primary open-angle glaucoma (POAG). MATERIALS AND METHODS: Eighty-one serial horizontal enhanced depth imaging optical coherence tomograph B-scans (interval between B-scans, ∼35 µm) of the nasal corneoscleral limbus were obtained before and 4 weeks after SLT. Fifty B-scans in the overlapping regions before and after SLT were selected for analysis based on the structures of aqueous and blood vessels as landmarks. The SC cross-sectional area (CSA) was measured in each selected B-scan and averaged to generate the mean SC CSA of the eye. SC volume in the overlapping region was calculated using commercially available 3-dimensional reconstruction software. The mean SC CSA and SC volume were compared between pre-SLT and post-SLT B-scans. Correlation analysis was performed between SC CSA changes and intraocular pressure (IOP) changes. RESULTS: Thirteen POAG eyes (13 patients) were included for analysis (mean age, 68.2±9.2 y). After SLT, the mean IOP was reduced from 19.8±7.6 to 14.4±3.8 mm Hg (P=0.003); the mean SC CSA increased by 8%, from 2478±550 to 2682±598 µm (P=0.029); and the mean SC volume increased from 4,304,592±954,777 to 4,658,250±1,039,956 µm (P=0.029). Increase in SC CSA had a significant positive correlation with IOP reduction after SLT (P=0.023, R=0.622). CONCLUSIONS: SLT expands SC in POAG patients and even more so with greater IOP reduction after SLT. Post-SLT expansion of SC may be due to increased trabecular aqueous outflow, IOP decrease, or structural changes in trabecular meshwork resulting from SLT.

Effect of Cyclopentolate on In Vivo Schlemm Canal Microarchitecture in Healthy Subjects.

PURPOSE: To characterize the in vivo effect of cyclopentolate on the microstructure of Schlemm canal (SC) in healthy eyes. METHODS: For healthy subjects, 81 serial horizontal enhanced depth imaging optical coherence tomography B-scans (interval between scans, ∼35 µm) of the nasal corneoscleral limbal area were obtained before and 1 hour after cyclopentolate 1% administration in 1 eye. The structures of aqueous and blood vessels in each scan were used as landmarks to select 50 overlapping scans between the 2 sets of 81 serial scans (before and after cyclopentolate administration). The SC cross-sectional area was measured in each of the 50 selected scans. After 3-dimensional reconstruction, SC volume was determined. RESULTS: Twelve eyes (12 healthy subjects) were imaged successfully before and after cyclopentolate administration. Mean age was 27.8±4.9 years (range, 25 to 38 y). Following cyclopentolate administration, mean intraocular pressure did not change significantly (13.9±1.5 to 14.2±1.5 mm Hg; P=0.19). Mean SC cross-sectional area decreased by 17%, from 3563±706 to 2959±460 µm (P<0.001). Mean SC volume in the overlapping area (approximately 1.7 mm of circumferential length of SC) decreased from 6,164,061±1,220,787 to 5,119,462±794,763 µm (P<0.001). The decrease in the mean SC cross-sectional area after cyclopentolate administration was greater in eyes with larger baseline SC cross-sectional area (P<0.001, R=0.873). CONCLUSIONS: Cyclopentolate causes a reduction in SC dimensions in healthy eyes. Future studies are warranted to determine the exact mechanism(s) of this change.

Optic Nerve Head Drusen Prevalence and Associated Factors in Clinically Normal Subjects Measured Using Optical Coherence Tomography.

OBJECTIVE: To investigate the prevalence of optic nerve head drusen (ONHD) in clinically normal subjects using enhanced depth imaging (EDI) optical coherence tomography (OCT) and to evaluate associated factors. DESIGN: Prospective, cross-sectional, observational study. PARTICIPANTS: Total of 130 clinically normal subjects. METHODS: Serial horizontal and vertical EDI OCT B-scans (interval between scans, ∼30 µm) of the optic nerve head (ONH) were obtained in both eyes of clinically normal subjects. Signs of ONHD were defined as horizontal hyperreflective bands perpendicular to the OCT beam with or without a signal-poor core. The minimum length of isolated hyperreflective bands was determined based on analysis of 34 eyes with clinically definite ONHD. Age, gender, ONH diameter, and axial length were obtained from participants. MAIN OUTCOME MEASURES: Prevalence of ONHD in clinically normal subjects and its association with age, gender, ONH diameter, and axial length. RESULTS: Based on the measurements of 94 isolated hyperreflective bands in the 34 eyes with clinically definite ONHD, the minimum length of isolated hyperreflective ONHD bands in clinically normal subjects was set as 45 µm (mean minus 2 standard deviations). Among 260 clinically normal eyes (130 subjects; 68 women; mean age, 40±17 years), EDI OCT was positive for horizontal hyperreflective ONHD bands in 28 eyes (10.8%) of 19 subjects (14.6%). Of these 28 eyes, 25 eyes (9.6% of total 260 eyes) of 16 subjects (12.3% of total 130 subjects) showed isolated hyperreflective bands with no signal-poor core, and 3 eyes (1.2% of total 260 eyes) of 3 subjects (2.3% of total 130 subjects) showed a signal-poor core surrounded by hyperreflective bands. No significant differences were found in mean age (44 vs. 39 years; P = 0.121) or gender distribution (56% vs. 52% female; P = 0.766) between clinically normal subjects with hyperreflective ONHD bands and those without. Logistic regression analysis showed that a decrease in ONH diameter by 100 µm and axial length by 1 mm increased the odds of ONHD presence by 1.5-fold (odds ratio [OR] = 1.56 [confidence interval (CI), 1.22-2.00]; P < 0.001) and 2-fold (OR = 2.00 [CI, 1.15-3.49]; P = 0.015), respectively. CONCLUSIONS: Subclinical ONHD may be more prevalent than previously believed. Significant associations of subclinical ONHD with smaller ONH and shorter axial length were found.

Characteristics and variations of in vivo Schlemm's canal and collector channel microstructures in enhanced-depth imaging optical coherence tomography.

BACKGROUND/AIMS: To characterise in vivo Schlemm's canal (SC) and collector channels (CC) microstructures using enhanced-depth imaging (EDI) optical coherence tomography (OCT). METHODS: Serial horizontal EDI OCT B-scans (81 scans, 15×5° rectangle) were prospectively obtained in the nasal and temporal limbus. SC cross-sectional area (CSA) was measured by delineating its lumen in each B-scan. CCs connected to SC were counted. SC CSA and the number of CCs were compared between the nasal and temporal areas. RESULTS: Eleven eyes (11 normal subjects) were included (mean age, 28±5 years). SC and CCs were clearly demarcated in EDI OCT B-scans with excellent repeatability and reproducibility (intraclass correlation coefficients, 0.830-0.886 and 0.793, respectively; all p<0.001). SC CSA varied considerably among subjects, ranging from 1664 to 6007 µm2 (average, 3514±1235 µm2), and among different regions of the same eye with coefficient of variation in each eye ranging from 23% to 46% (average, 32±7%). The number of CCs in the analysed area also varied considerably among subjects, ranging from 5 to 11 (average, 8.73±1.85). The mean SC CSA (3839±1402 µm2 vs 3189±1209 µm2; p=0.033) and number of CCs (5.5±1.4 vs 3.3±1.1; p=0.001) were significantly greater nasally than temporally. The mean SC CSA was significantly correlated with the number of CCs (r=0.635, p=0.036). CONCLUSIONS: High-quality images of the aqueous outflow pathway can be obtained with a clinical device, avoiding postacquisition processing. In vivo SC and CC microstructures vary considerably among individuals and regions. SC tends to be larger in regions with more CCs.

Glaucoma Diagnostic Capability of Global and Regional Measurements of Isolated Ganglion Cell Layer and Inner Plexiform Layer.

PURPOSE: To compare glaucoma diagnostic capability of global/regional macular layer parameters in different-sized grids. MATERIALS AND METHODS: Serial horizontal spectral-domain optical coherence tomography scans of macula were obtained. Automated macular grids with diameters of 3, 3.45, and 6 mm were used. For each grid, 10 parameters (total volume; average thicknesses in 9 regions) were obtained for 5 layers: macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), ganglion cell-inner plexiform layer (GCIPL; GCL+IPL), and ganglion cell complex (GCC; mRNFL+GCL+IPL). RESULTS: Sixty-nine normal eyes (69 subjects) and 87 glaucomatous eyes (87 patients) were included. For the total volume parameter, the area under the receiver operating characteristic curves (AUCs) in 6-mm grid were larger than the AUCs in 3- and 3.45-mm grids for GCL, GCC, GCIPL, and mRNFL (all P<0.020). For the average thickness parameters, the best AUC in 6-mm grid (T2 region for GCL, IPL, and GCIPL; I2 region for mRNFL and GCC) was greater than the best AUC in 3-mm grid for GCL, GCC, and mRNFL (P<0.045). The AUC of GCL volume (0.920) was similar to those of GCC (0.920) and GCIPL (0.909) volume. The AUC of GCL T2 region thickness (0.942) was similar to those of GCC I2 region (0.942) and GCIPL T2 region (0.934) thickness. CONCLUSIONS: Isolated macular GCL appears to be as good as GCC and GCIPL in glaucoma diagnosis, while IPL does not. Larger macular grids may be better at detecting glaucoma. Each layer has a characteristic region with the best glaucoma diagnostic capability.